im growing from manchester also hit by this heatwave!
like u jus taken some cuttings, but instead of using soil i always start of using rockwool cubes, or if you can try and find a product named "root riot" this seems to work too
but if like me you are on a low buget them rockwool is the answer!
ur light set up should be fine, but once the girls grow roots try and introduce a HPS light, or equiv.!!

Hydro